/**
 * /* eslint-disable
 *
 * @format
 */

import { Buffer } from 'https://deno.land/std@0.110.0/node/buffer.ts';

import Long from '../../../utils/long.ts';
// Based on the kafka client 0.10.2 murmur2 implementation
// https://github.com/apache/kafka/blob/0.10.2/clients/src/main/java/org/apache/kafka/common/utils/Utils.java#L364

const SEED = Long.fromValue(0x9747b28c);

// 'm' and 'r' are mixing constants generated offline.
// They're not really 'magic', they just happen to work well.
const M = Long.fromValue(0x5bd1e995);
const R = Long.fromValue(24);

export default (key: any) => {
  const data = Buffer.isBuffer(key) ? key : Buffer.from(String(key));
  const length = data.length;

  // Initialize the hash to a random value
  let h = Long.fromValue((SEED as any).xor(length));
  let length4 = Math.floor(length / 4);

  for (let i = 0; i < length4; i++) {
    const i4 = i * 4;
    let k =
      (data[i4 + 0] & 0xff) +
      ((data[i4 + 1] & 0xff) << 8) +
      ((data[i4 + 2] & 0xff) << 16) +
      ((data[i4 + 3] & 0xff) << 24);
    k = Long.fromValue(k);
    k = (k as any).multiply(M);
    k = (k as any).xor((k as any).toInt() >>> R);
    k = Long.fromValue(k).multiply(M);
    h = h.multiply(M);
    h = h.xor(k);
  }

  // Handle the last few bytes of the input array
  switch (length % 4) {
    case 3:
      h = h.xor((data[(length & ~3) + 2] & 0xff) << 16);
    case 2:
      h = h.xor((data[(length & ~3) + 1] & 0xff) << 8);
    case 1:
      h = h.xor(data[length & ~3] & 0xff);
      h = h.multiply(M);
  }

  h = h.xor(h.toInt() >>> 13);
  h = h.multiply(M);
  h = h.xor(h.toInt() >>> 15);

  return h.toInt();
};
